Pixels. Pixels are those square things in a picture that take in a specific amount of light when you take the picture. Each small pixel when put together makes beautiful pictures like the ones you see below. The amount of light each pixel gets is called its pixel value. If it has a very high pixel value like 3000, the pixel will be very bright. If the pixel has a very low pixel value, like 100, the pixel will be black or a dark grey. When, adjusting an image, you can set the highest pixel value that want to allow in you pic, and the lowest. If one of the pixels in your pic are higher (for example, a pixel with a value of 4000) than the maximum pixel value (in this case, lets say 3000, again), the pixel will be the same shade (extremely white) as a pixel that's 3000 because you don't allow the others to show a difference. If one of the pixels (with a value of, lets say, 50) is below the minimum (e.g. 100), the pixel will be a really dark black just like a pixel of 100 or lower. But, the pixels with a value in between the max. and min. of the pic, will be different shades of gray based on how they are compared to the max. and min.
| This is the Andromeda Galaxy, the max pixel value is 4095 and the min value is 1072 |
| This is also the Andromeda. Max: 2028 Min: 543 |
| ^^^ Andromeda again Max: 1644 Min: 433 |